BACKGROUND
[0001] The present application relates to power supplies for electrical appliances.
[0002] Recent years have seen a proliferation of portable electrical appliances. Digital
cameras, media players, mobile telephones, and global positioning system (GPS) devices
are but a few examples of this trend. In many cases, these devices are provided with
a power adapter that converts power from a power source such as an alternating current
(AC) power line to a form used by the appliance.
[0003] Unfortunately, losses in the power adapter can degrade the energy efficiency of the
system. This problem is exacerbated by the fact the power adapters are often left
connected to the input power source for extended periods of time.
[0004] In the ubiquitous case of a mobile telephone, for example, the phone is connected
to a power adapter, at which the point an onboard charger may enter an active charging
mode in which the batteries are brought to a fully charged state. If the phone is
not disconnected from the power adapter, the charger may enter a maintenance mode
in which power from the adapter is used to maintain the battery state of charge. At
some point, the mobile phone is typically disconnected from the adapter and used as
desired. Nonetheless, the charger is often not unplugged from the power outlet.
[0005] Another trend has been an increased emphasis on energy efficiency. As result, manufactures
have sought to improve the energy efficiency of their power adapters, for example
by using relatively more efficient electrical components and circuit configurations
such as switched mode power converters. In the U.S., these efforts have gained increasing
visibility through the Energy Star® program promulgated by the U.S. Environmental
Protection Agency. Those products that meet certain energy efficiency criteria may
receive the Energy Star qualification and display the Energy Star certification mark.
See, e.g., Energy Star Program Requirements for Products with Battery Charging Systems (Draft
2); Energy Star Program Requirements for Single Voltage External AC-DC and AC-AC Power
Supplies (Draft 1.1).
[0006] Nonetheless, there remains room for improvement.
[0007] US 5,761,083 discloses a power supply corresponding to the preamble of claim 1.
[0008] US 2006/0072262 discloses a power supply that comprises a power converter that receives electrical
power and supplies electrical power to an electrical appliance, a communication interface
and wherein the input power source is an electrical power system that is subject to
a time varying power demand and the power supply includes a load shifter that temporally
shifts an electrical load presented by the appliance from a time of relatively higher
demand to a time of relatively lower demand.
SUMMARY
[0009] Aspects of the present invention address these matters, and others.
[0010] The present invention relates to a power supply comprising:
a power converter configured to receive electrical power from an input power source
and configured to supply electrical power to a connectable electrical appliance;
a communication interface configured for communication with the connectable electrical
appliance and a component of the power supply; and
wherein the input power source is an electrical power system that is subject to a
time varying power demand and the power supply includes a load shifter configured
to temporally shift an electrical load presented by the connectable electrical appliance
from a time of higher demand to a time of lower demand,
characterized in that the input power source is characterized by a time varying power
output capability, the power converter is characterized by a time varying power output
capability that varies as a function of the input power source power output capability,
the power supply includes a power output capability determiner configured to generate
a time varying output indicative of the power output capability of the power converter,
and wherein information indicative of the determined capability is communicated to
the appliance via the communication interface.
[0011] Preferred embodiments of the invention are apparent from the dependent claims.
[0012] Those skilled in the art will recognize still other aspects of the present invention
upon reading and understanding the attached description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention is illustrated by way of example and not limitation in the
figures of the accompanying drawings, in which like references indicate similar elements
and in which:
Figure 1A depicts a power source, power supply, and electrical appliance.
Figure 1B depicts a prior art switched mode power converter.
Figures 2A-2D depict power supplies.
Figures 3A-3D depict electrical appliances.
Figure 4A depicts a power supply and an electrical appliance, not covered by the scope
of the invention;
Figures 4B and 4C depict interactions between the power supply and appliance, also
not covered by the scope of the invention.
Figure 5A depicts first and second power supplies and an electrical appliance, not
covered by the scope of the invention.
Figure 5B depicts interactions between the appliance and the power supplies, also
not covered by the scope of the invention.
Figure 6A depicts a power supply and an electrical appliance, not covered by the scope
of the invention;
Figure 6B depicts an interaction between the power supply and the appliance, also
not covered by the scope of the invention.
Figure 7A depicts a power supply and an appliance; Figure 7B depicts an interaction
between the power supply and the appliance.
Figure 8 depicts an interaction between a power supply and an appliance.
Figure9 depicts an interaction between a power supply and an appliance, not covered
by the scope of the invention.
DETAILED DESCRIPTION
[0014] With reference to Figure 1, an apparatus 100 includes a power supply 104 and an electrically
powered appliance 106.
[0015] The electrically powered appliance 106 may be any device that is powered by electrical
power, including but not limited to devices configured for use in the consumer, commercial,
or industrial environments. Non-limiting examples of electrically powered appliances
106 include devices such as cellular or mobile telephones, domestic appliances, cordless
telephones, answering machines, lighting devices, music or media players, personal
digital assistants (PDAs), laptop, handheld, or notebook computers, optical bar code
or other scanners, communications equipment, global positioning system (GPS) devices,
and portable test and measurement equipment. Preferably, however, the electrical appliance
106 is configured as a human-portable device including a housing 107 that can be carried
by, or otherwise moved under the power of, a human user.
[0016] As illustrated, the appliance 106 includes a connector 110 that provides removable
data and power connections to the power supply 104 or other external device(s) via
suitable wires or cables. The connector 110 may also be configured to include multiple
connectors (
e.g., physically separate data and power connectors). Power and data may also be transferred
over the same wire(s) (
e.g., using a suitable modulation scheme) or suitable wireless connection(s). Device
electrical circuitry 120 performs a function of the appliance 106.
[0017] Some examples of suitable wireless connections include inductive, radio frequency
(RF), optical, and the like for power and/or data and includes combinations thereof,
including wired connections. For example, the connector 110 may employ inductive for
power transfer and optical for data. As another example, the connector 110 may employ
optical for power and a wire or cable for data.
[0018] An inductive wireless connection is one where electrical energy is converted to a
magnetic energy field by means of circuitry that drives electrical current in a conductor,
typically a coil of wire. Magnetic energy radiates from a first, primary coil. A second
conductor, typically a coil, when near the primary coil is influenced by the magnetic
field radiating from the primary coil. That is to say the primary coil radiates into
the vicinity of the secondary coil. As a result, the changing magnetic field induces
a current to flow in the secondary coil which can be harvested by means of appropriate
circuitry for immediate use or storage in appropriate electrical energy storage devices
such as a battery, capacitor or electrochemical capacitor. An inductive wireless connection
could also be used to transmit data by modulating the inductive signal in a manner
so as to encode instruction on the inductive signal. Size, shape, orientation and
number of windings are important criteria when designing the coils for an inductive
wireless connection.
[0019] An RF wireless connection is one where electrical energy is converted to radio frequency
energy (RF) by means of circuitry that drives an RF generator and broadcast antenna.
Many antenna designs are contemplated including ones that radiate with a wide radiation
pattern to cover a broad area. Other applications may benefit from antenna patterns
that are narrow in radiation pattern to avoid interference or allow for longer broadcast
ranges or higher received power by the receiver. An RF receiver is also needed on
the secondary side of the RF wireless connection. The RF receiver has an antenna that
will receive the RF energy from the transmitter and convert it to useable signal energy
in the secondary part of the wireless connection. This wireless connection can be
used to transfer power and or data or both.
[0020] An optical wireless connection is one where the electrical energy is converted to
optical energy, photons, by means of a light source. Light Emitting Diodes (LEDs)
are one such light source that converts electrical energy to optical energy. Other
optical energy sources are also contemplated including incandescent, fluorescent,
halogen, metal halide, etc. The secondary side of the optical wireless connection
is here the optical energy is converted back to electrical energy. A photodiode, photovoltaic
cell such as a solar cell, or other suitable device is used to receive the optical
energy and convert it back to electrical energy for use as either a power source,
data signal or both.
[0021] In a preferred embodiment the electrical energy may be transmitted by means of a
wire or cable and the data be transmitted by means of RF. In another embodiment the
electrical power may be transmitted by means of a wireless inductive link and the
data is transmitted by means of an optical wireless connection. One skilled in the
art can imagine using any number of combinations depending on the application need.
[0022] In one example, the connector 110 employs inductive energy as a method for receiving
power. The connector 110, in this example, can include a secondary coil (not shown)
to wirelessly receive power.
[0023] As will be described further below, the appliance 106 may also include a rechargeable
power source 122 such as one or more secondary (rechargeable) batteries, capacitors,
electrochemical capacitors, capacitive energy storage devices, or the like that supply
operating power to the device electrical circuitry 120, as well as a charger 124 that
charges the storage device 122. As will also be described further below, the appliance
may also include one or more of appliance power requirements or other information
128, a disconnect requester 130, a load shifter 132, and a mode controller 134.
[0024] The power supply 104, which is likewise configured to be human-portable and includes
a housing 103, receives electrical power from an input power source 102 such as a
standard 120/240 volt alternating current (VAC) 50/60 Hertz (Hz) power outlet, a vehicular
power system such as a nominal 12 volt direct current (VDC) automobile electrical
system, a renewable energy source such as a solar or wind source, mechanical source
such as crank or vibration source, an infrared (IR) or heat source, an electromagnetic
source, or other source of electrical power. The input power source 102 typically
includes an electrical connector 108 such as a standard wall or other electrical outlet,
a 12 VDC power socket, or the like that allows various devices to be removably connected
to the power source 102. While the power supply 104 power rating is typically a function
of the electrical appliance(s) 106 with which it is designed to operate, ratings ordinarily
range between about 2 and 150 Watts (W), and often toward the lower end of the range.
[0025] The power supply 104 also includes an input power connector 112 such as a standard
AC plug, 12 VDC power plug, or the like that matingly engages or otherwise connects
to the connector 108 of the input power source 102. Connector 112 may also be configured
to be a non contact or wireless connector that employs methods or means of wireless
power and/or data transfer for connections. Various methods of wireless power transmission
techniques are contemplated including but not limited to: inductive, radio frequency
(RF), optical power transfer or a combination of any method.
[0026] In one example, the connector 112 includes a secondary coil for receiving inductive
power.
[0027] A power converter 105 converts power from the input power source 102 to the voltage
and/or current levels required by the appliance 106. Also in the illustrated embodiment,
the power supply 104 includes a connector 114 that connects to the connector 110 of
the appliance 106. While only a single connector 114 and appliance 106 is illustrated,
it will be understood that the power supply 104 may include a plurality of connectors
114 or otherwise be configured to concurrently connect with a plurality of appliances.
[0028] Connector 114 may also be configured to be a non contact or wireless connector that
employs methods or means of wireless power and/or data transfer, wireless connections.
Various methods of wireless power transmission techniques are contemplated including
but not limited to: inductive, radio frequency (RF), optical power transfer or a combination
of any method. For example, in one embodiment the wireless power transmission technique
may be an inductive connection with the data communication provided by an optical
wireless connection.
[0029] In one example, the connector 114 employs inductive energy for providing power. The
connector 114, in this example, includes a primary coil to wirelessly provide power.
[0030] Examples of suitable power converters 105 include linear and switched-mode power
converters. Linear power converters are well suited for use with AC input sources
102 and typically include an input transformer that operates at the frequency of the
input power source 102 (
e.g., 50/60 Hz in the case of a power supply 104 configured to operate with a standard
AC power outlet). Switched-mode power converters typically include a relatively high
speed semiconductor or other switch operatively connected to a reactor such as an
inductor or capacitor.
[0031] Various linear and switched mode power converter topologies are known in the art
and may selected based on application specific requirements. While linear power converters
tend to be simple and robust, they also tend to be relatively bulky and inefficient.
Though more complex, switched mode power converters are as a rule smaller and more
energy efficient than comparable linear power converters. Moreover, switched mode
power converters are generally better suited for use where the input power source
102 is a direct current (DC) source or where the power supply 104 is designed to operate
with multiple power sources 102 (
e.g., with both 120 VAC/60 Hz and 240 VAC/50 Hz systems).
[0032] A block diagram of an example switched mode power converter that includes closed
loop feedback control is shown in Figure 1B. As illustrated, an input rectifier and/or
filter 150 receives input power from a source such as the AC power mains, and the
output of the rectifier is provided to a switch 152 that serves as an inverter or
chopper. The chopper, which typically operates at a switching frequency on the order
of tens to hundreds of kilohertz (KHz), is connected electrically in series with the
primary winding of a transformer 154, and the transformer secondary winding(s) is
connected to an output rectifier(s) and/or filter(s) 156 that produce a DC output
signal. A closed loop controller 158 controls an operation of the chopper 152 so as
to regulate the power converter output voltage.
[0033] In the case of an inductive wireless connection power is received by means of the
secondary coil acted on by the changing magnetic field from the primary coil. The
magnetic energy induces a current flow in the secondary coil that must be captured
by the secondary circuit. A preferred method to capture this energy would be through
the use of semiconductor such as a diode operatively connected to a reactor such as
an inductor or capacitor that will serve as the input stage to the remainder of the
switch mode power supply discussed earlier.
[0034] As will be described further below, the power supply 104 may include one or more
of a communication interface 136 that communicates with a connected appliance 106,
a power supply capability determiner 138 that determines or otherwise provides time
varying or static information indicative of a power capability of the power supply
104 and/or a connected power source 102, a load prioritizer 140 that prioritizes power
provided to multiple appliances 106 in the case of a power supply 104 configured to
concurrently connect to more than one appliance 106, a load shifter 142 that shifts
a load presented to the power supply 104 and/or the connected power source 102, and
a power converter disconnect 144 that selectively disconnects at least a portion of
the power converter 105 from the input power source 102.
[0035] Various examples of the power supply 104 and appliance 106 will now be described,
it being understood that the described features and combinations of features are provided
for the purpose of illustration and may be selected or varied by one of ordinary skill
in the art upon reading and understanding the present description. Turning now to
Figure 2A, a power supply 202 is configured for power and data communication with
a connected appliance 106. As illustrated, the power supply 202 includes power supply
capability determiner 138, a communication interface 136, and a power converter 105.
[0036] The communication interface 136 provides uni- or bi-directional communication with
a connected appliance 106. In one implementation, the communication interface 136
is a universal serial bus (USB) interface, the power supply 202 serves as a USB powered
host, and the connector 114 is a standard USB connector though which data and power
are provided to a connected appliance 106. Note that other serial, parallel, analog
and digital communications interfaces 106 are also contemplated including wireless
inductive, radio frequency (RF) including but not limited to WiFi, Bluetooth, ZibBee
open standard protocols or other proprietary, closed protocols, RFID, optical, including
infrared (IR) and the like.
[0037] The power supply capability determiner 138 determines or otherwise provides information
indicative of the capabilities of the power supply 202 and/or an input power source
102. In one example, the information is static information describing a voltage, current,
or power rating of the power supply 202 or a power source 102. In another, the information
includes model number or similar identifying information that serves as a proxy for
the power supply 202 capabilities.
[0038] The power supply 202 capabilities, and hence the capability information, may also
be time varying. Where the power supply 202 receives power from a solar or wind source,
for example, the power available from the power converter 105 will typically vary
as a function of factors such as incident light or wind speed.
[0039] The determined power supply capability may be communicated to a connected device
106 via the communication interface 206, for example when an appliance 106 is initially
connected to the power supply 202, from time-to-time during operation of the devices,
or the like.
[0040] Turning now to Figure 2B, a second example power supply 220 is configured for power
communication with a connected appliance 106. While the power supply includes a power
converter 105, it lacks a communication interface. As a consequence, the power supply
220 does not support communication with a connected appliance 106 that includes communication
capabilities.
[0041] Turning now to Figure 2C, a third example power supply 230 is configured for data
and power communications with a connected appliance 106. As illustrated, the power
supply 230 includes a power converter 105, a communication interface 136 a load shifter
142, and a power converter disconnect 144.
[0042] In some situations, it may be desirable to shift an electrical load presented to
the power source 102 by the power supply 230 and a connected load 106 from a period
of relatively high power demand (
e.g., in the middle of the day for a typical electrical power grid) or limited power availability
(
e.g., in the middle of the night in the case of a solar power source 102) to a period
of relatively reduced demand or increased availability. To this end, the load shifter
142 may be employed to defer, bring forward, or otherwise shift an operation of the
appliance 106 from a time of high or peak demand or limited power availability to
a time of relatively lower demand or greater power availability. Information regarding
desired operating mode and/or load shifting operations may be communicated to and/or
from a connected appliance 106 via the communication interface 136, for example by
sending suitable commands and/or signals to the appliance 106.
[0043] The power supply 230 may also include a real time or other clock 210, load shift
schedule 212, and device operating mode information 214. The load shift schedule 212
includes desired starting and ending time(s) or other parameters relevant to a load
shifting operation. The operating mode information 214 provides information indicative
of possible operating mode(s) of appliance(s) 106 which the power supply 230 is designed
to operate.
[0044] Power converters 105 typically draw power from the input power source 202 even where
the power converter 105 is (substantially) unloaded, for example due to the non-ideal
characteristics of transformers, switching devices, reactors, and other practical
components. This power is ordinarily dissipated in the form of heat, and degrades
system energy efficiency.
[0045] The power converter disconnect 144 selectively disconnects the power converter 105
from the input power source 102. As illustrated, the power converter disconnect 144
is operatively connected to a switch 235 such as an electromechanical switch or relay,
semiconductor switching device, or the like located electrically in series between
the input power source 102 and the power converter 105.
[0046] Though illustrated as being located at the input of the power converter 105, the
switch 235 may be integral thereto. In one such example, the switch 235 is also the
inverter or chopper of a switched mode power converter, and the operation of the switch
235 is selectively enabled or disabled via suitable logic or other circuitry so as
to disconnect some or all of the power converter 105 from the input power source 102.
In another, the switch 235 is located after a rectifier and/or filter. The power converter
disconnect 144 can be employed to automatically (
i.e., without user intervention) reduce a power drawn by the power supply 230 from the
power source 102 during periods of inactivity or reduced load, for example in the
case of a connected appliance 106 that can be operated from a battery or other power
source internal to the appliance 106 while in a low power operating mode, when a secondary
(rechargeable) battery or other power source of the appliance 106 is fully or otherwise
substantially charged, when an appliance 106 is not connected to the power converter
105, in coordination with a load shifting operation, or the like.
[0047] The power supply 230 may include a rechargeable power source 236 that provides power
to desired portions of the power converter 230 when the power converter circuit 105
is disabled. Operating power may also be obtained from the connected appliance 106
or a portion of the power converter circuit 105 that is not disabled. Note that the
power supply 230 may also include a user operated power switch 238 that allows the
user to manually disconnect the power supply 230 from the input power source 102.
[0048] Another example of a power supply 240 configured for power and data communication
with a connected device is shown in Figure 2D. As illustrated, the power supply 240
includes as battery receiving region 242 configured to receive one or more generally
cylindrical AAA, AA, C, D-size, or other suitable batteries. Battery contacts 246
make electrical contact with the battery 244 terminals. In one implementation, the
batteries 244 supplant the power source 102, in which case the connector 112 may be
omitted. In another, the batteries 244 supply electrical power in the event of a power
loss, if the power supply 240 is unplugged, or the like. While not explicitly illustrated
in Figure 2D, it will be understood that the power supply 240 may also include one
or more of the power supply capability information 138, load shifter 142, power converter
disconnect 144, or load prioritizer 140.
[0049] A first example electrically powered appliance 302 configured for power communication
with a power supply 104 is shown in Figure 3A. As illustrated, the appliance 302 includes
device electrical circuitry 120, a rechargeable power source 122, a charger 124, and
a connector 110. The charger 124 includes a state of charge detector that detects
a state of charge of the energy source, for example by measuring a source voltage
or current or, in the case of a timer based charger, an elapsed charging time. Note
that the device electrical circuitry 120 may be omitted and the appliance 302 configured
as a battery charger, in which case the appliance 302 ordinarily includes a battery
receiving region 242 and battery contacts 246 analogous to those described above in
relation to Figure 2D and configured to accept batteries of the number and size(s)
to be charged. According to such an implementation, batteries are ordinarily inserted
in the battery receiving region 242 for charging and removed for use in another device.
[0050] As the appliance 302 lacks a communications interface, the appliance 302 does not
support communication with a power supply 104 that includes communication capabilities.
[0051] A second example electrically powered appliance 320 configured for power and data
communication with a power supply 104 is shown in Figure 3B. As illustrated, the appliance
320 includes a connector 110, a data communication interface 322, device electrical
circuitry 120, appliance requirements information 128, a load shifter 132, and a disconnect
requester 130. Where the voltage and/or current requirements of the device electrical
circuitry 120 differ from those provided by a connected power supply 104, an optional
power converter may be used to convert the power from the power supply 104 to the
required voltage and/or current levels.
[0052] The load shifter 132 performs a temporal load shifting operation and may operate
in conjunction with one or more of an onboard clock(s), load shift schedule, and operating
mode information. The load shifter 132 causes the appliance 320 to perform a load
shifting operation. In one example, the load shifting is performed in response to
a request communicated by a connected power supply 104 via the respective communications
interfaces. In another example, the load shift operation is initiated by the load
shifter 132 and optionally communicated to a connected power supply 104.
[0053] The disconnect requester 130 generates a signal or other request to cause some or
all of the power converter 105 of a connected power supply 104 to disconnect from
its input power source 102. In one example, the disconnect request is generated when
the device electrical circuitry 120 enters an inactive state or mode. Where, as illustrated,
the appliance 302 lacks an energy storage device, initiating a disconnect request
will ordinarily de-power the device electrical circuitry 120.
[0054] Another example of an electrically powered appliance 340 configured for data and
power communication with a connected power supply 104 is shown in Figure 3C. As illustrated,
the appliance 340 includes a charger 124, rechargeable power source 122, and device
electrical circuitry. The appliance 340 also includes a communication interface 126,
load shifter 132, mode controller 134, and a disconnect requester 130.
[0055] As illustrated, the disconnect requester 130 is operatively connected to the charger
124, for example to generate a disconnect request when the rechargeable power source
122 is substantially or otherwise suitably charged. The disconnect requester 130 may
also from time-to-time generate a reconnect request, for example to maintain the storage
device 122 state of charge.
[0056] As the appliance 340 includes an energy storage device 122, at least a portion of
the device electrical circuitry 120 remains substantially functional when the appliance
340 is disconnected from a power source 104 or where a power converter 105 is disconnected
from the input power source 102.
[0057] The mode controller 134 controls an operating mode of the device electrical circuitry
120. In one example, the mode controller 134 varies an operating mode of the appliance
in response to a signal generated by a connected power supply 104 and communicated
via the respective communication interface. In another example, the mode controller
134 may restrict the device electrical circuitry 120 to a relatively low power or
otherwise limited operating mode(s) when the appliance is not connected to a power
supply 104.
[0058] Another example of an electrically powered appliance 350 is shown in Figure 3D. As
illustrated, the appliance 350 includes a connector 110 and a device electrical circuitry
120. As the appliance 350 does not include a communication interface or an energy
storage device, the appliance 350 does not support data communication with a connected
power supply 104 and is ordinarily non-functional when not connected to a power supply
104.
[0059] The various power supplies 202, 220, 230, 240 and electrical appliances 302, 320,
340, 350 may form a family of generally interoperable devices, noting again the features
and combinations of features described above are presented for the purpose of illustration
and may be varied to suit the requirements of a particular application. Viewed from
the perspective of the electrical appliances, a given electrical appliance may be
configured to operate with some or all of the power supplies 202, 220, 230, 240. Viewed
from the perspective of the power supplies, a given power supply may be configured
to operate with some or all of the electrical appliances 302, 320, 340, 350. According
to such an implementation, the connectors 114, 110 of the power supplies and electrical
appliances are preferably physically compatible, and the communications interfaces
operate according to a common communication protocol.
[0060] Following their connection, a power supply 104 and electrical appliance 106 undergo
a detection and/or identification process (
e.g., an enumeration process in the case of devices having a USB interface) in which
those devices having a communication interface seek to identify the device to which
it is connected and determine power requirements. Where a device having a communication
interface is connected to a device that does not include a communication interface
or to an otherwise unrecognized device, the communicative device enters into a default
or otherwise pre-defined mode of operation. Where two communicative devices are connected,
the devices interact accordingly.
[0061] Various example interactions will now be presented, it again being understood that
the examples should not be construed as limiting the types or configurations of the
devices and/or the possible interactions.
[0062] Turning first to Figure 4A (not covered by the scope of the invention), a power supply
402 is configured as a wall plug adapter that plugs into a standard 120 VAC wall or
other outlet 406, and an electrical appliance 404 is a consumer electronic device
such as a cellular or mobile telephone that includes a rechargeable battery. As illustrated,
the adapter 402 includes a generally rectangular prismatic housing 408 having a standard
AC power plug that protrudes from a surface of the housing 408 so as to plug into
the outlet 406. A connector 412 located at the distal end of a cable 414 removably
engages a corresponding connector of the mobile phone 404.
[0063] In a first example, the power supply 402 is configured as described in Figure 2B
and the appliance 404 is configured as described in Figure 3A. The device 402, 404
interaction will now be described with reference to Figure 4B (not covered by the
scope of the invention), it being assumed that the power supply 402 is already plugged
in to the outlet 406. At 420, the power supply 402 and the appliance 404 are connected.
At 422, power from the power supply 402 is used to charge the appliance 404 battery.
At 424, the devices are disconnected, and the appliance 404 is operated at step 426.
Of course, the process may be repeated as desired.
[0064] As will be appreciated by those of ordinary skill in the art, the foregoing describes
a conventional interaction between a wall plug adapter and a mobile phone. While such
an interaction has proven to be effective for charging the appliance 404 battery,
there nonetheless remains room for improvement. For example, the power converter circuitry
105 of the wall plug adapter 402 remains connected to the power mains 406 even after
the battery of the mobile phone 404 is substantially fully charged, thus reducing
the overall energy efficiency of the arrangement. Trickle charging of the battery,
if provided, further reduces the energy efficiency. Moreover, such an arrangement
does not support operations such as load shifting.
[0065] In a second example, the wall power supply 402 is configured as described in Figure
2C, while the appliance 404 includes a charger 124, rechargeable power source 122,
device electrical circuitry 120, a communications interface 126, and a disconnect
requester 130. A device 402, 404 interaction that includes a power supply disconnection
and reconnection operation will now be described with reference to Figure 4C (not
covered by the scope of the invention), it again being assumed that the power supply
402 is already plugged into the outlet 406 but that the power converter 105 is disconnected
from the AC power line.
[0066] The power supply 402 and appliance 404 are connected at step 430.
[0067] At 432, the devices undergo a detection and/or identification procedure 432, for
example to detect the other the connected device and identify its capabilities.
[0068] The power supply power converter 105 is connected to the AC power line at step 434.
[0069] At 436, the power supply 402 supplies power to the appliance 404, with the supplied
power being used to charge the storage device 122.
[0070] The state of charge of the storage device 122 is determined at 437, for example by
monitoring a device 122 voltage or current, determining an elapsed charge time in
the case of a timer based charger, or the like. If the storage device 122 is not sufficiently
charged, the charging process continues at step 436.
[0071] If the storage device 122 is substantially or otherwise sufficiently charged, at
least a portion of the power converter circuit 105 is disconnected from the AC power
mains 406 at step 438. In one example, a disconnect, charge complete, or other suitable
signal is communicated from the appliance 404 to the power supply 402 via the devices'
respective communication interfaces. Note that appliance 404 may be configured to
communicate such a signal even though the power supply 402 does not include a communication
interface or support a power converter disconnection operation, in which case the
request would not be honored. In another example, the state of charge detector is
included in the power supply 402, and the power converter 105 is disconnected accordingly.
[0072] The storage device 122 state of charge is maintained at step 440. For example, the
state of charge may be determined as described above in step 437. If a maintenance
or additional charge is required, a connect, charge required, or other suitable signal
may be communicated to the power supply 402 via the communication interfaces. Where
the state of charge is monitored by the power supply 402, the power converter 105
is connected accordingly. The process returns to step 434.
[0073] At 442, the appliance 404 and power supply 402 are disconnected, and the appliance
404 is operated at step 444. Note also that the disconnection of the appliance may
be detected and the power converter disconnected accordingly. The process may be repeated
as desired.
[0074] As will be appreciated, disconnecting the power converter 105 during periods of inactivity,
in which the electrical appliance 404 presents a relatively low load, or where the
appliance 404 is not connected to the power supply 402, and reconnecting the power
converter from time-to-time on an as needed basis tends to improve the overall energy
efficiency of the system. It will also be understood that the process be used in connection
with appliances other than mobile phones and the connection and reconnection performed
for purposes other than maintaining a battery state of charge. Thus, for example,
the appliance 404 may alternate between a relatively low power or sleep mode and a
relatively higher operating mode, with the power converter 105 being disconnected
and reconnected accordingly.
[0075] Turning now to Figure 5A (not covered by the scope of the invention), an example
family of devices includes a first power supply 502, a second power supply 504, and
an electrical appliance 506. As illustrated, the first power supply 502 is a wall
plug adapter similar to that described above in connection with Figure 4A. The second
power supply 504, which is configured to connect to an input power source having a
relatively lower power capability such as a power port 508 of a 12VDC vehicular power
system, includes a standard 12 VDC power connector 510 and an appliance connector
512.
[0076] The electrical appliance 506 includes at least a first relatively high power operating
mode and a second relatively low power operating mode. Where the appliance 506 is
configured as or includes a battery charger, for example, the electrical appliance
may include a relatively high power fast charging mode and a relatively low power
slow charging mode. As another example, a lighting appliance may include high and
low brightness modes.
[0077] In the present example, the first 502 and second 504 power supplies are both configured
as described above in relation to Figure 2A, and the electrical appliance 506 is configured
as described in relation to Figure 3C. An interaction between the appliance 506 and
the power supplies 502, 504 that includes a capability determination and operating
mode adjustment operation will now be described with reference to Figure 5B (not covered
by the scope of the invention). The electrical appliance 506 and a desired power supply
502, 504 are connected at step 520.
[0078] At 522, the devices undergo a detection and/or identification procedure to determine
the capability of the connected power supply 502, 504 and/or its input power source.
[0079] At 524, the appliance 506 enters into an operating mode consistent with the determined
capabilities of the connected power supply 502, 504. Where the appliance is connected
to the first power supply 502, for example, the appliance enters the relatively high
power operating mode. If the appliance is connected to the second power supply 504,
the appliance 506 enters the low power operating mode.
[0080] At 526, the electrical appliance 506 and power supply are disconnected.
[0081] The appliance is operated as desired at 528. Again, the process may be repeated as
desired.
[0082] Turning now to Figure 6A (not covered by the scope of the invention), an example
input power source 602, power supply 604, and appliance 606 are connected as shown.
For the purposes of this example, it will be assumed that the power supply is configured
as shown in Figure 2B and that the appliance 606 is configured as shown in Figure
3A. An example interaction between the devices that includes a charging discontinuation
operation will now be described with reference to Figure 6B (not covered by the scope
of the invention). The power supply 604 and appliance 606 are connected at 608.
[0083] At 610, the connected devices undergo a detection and/or identification procedure.
As the power supply 604 does not include a communication interface, the appliance
606 will recognize that it is connected to power supply 604 that does not support
communications and enters a suitable default or otherwise pre-defined operating mode.
[0084] At 612, power from the power supply 604 is used to charge the appliance 606 battery.
[0085] The battery state of charge is determined at 614. If the battery is not substantially
or otherwise suitably charged, the process continues to step 612.
[0086] If the battery is charged, charging is discontinued at 616, and the process returns
to step 614.
[0087] The appliance 606 is disconnected from the power supply 604 at 618 and may be operated
as desired at step 618. The process may be repeated as desired.
[0088] Turning now to Figure 7A, an example power supply 700 includes a solar cell or other
solar power source 702, a power converter 105, and power supply capability determiner
138. The appliance 704 is configured substantially as described in Figure 3C. A device
700, 704 interaction that includes a dynamic power capability determination and operating
mode adjustment will now be described with reference to Figure 7B.
[0089] The power supply 700 and appliance 704 are connected at 710.
[0090] At 712, the then-current power capability of the power supply 702 is detected and
communicated to the appliance 704 via the respective communication interfaces.
[0091] At 714, the appliance 704 enters an operating mode consistent with the communicated
capability, and the process continues to step 712.
[0092] At 716, the appliance 704 and power supply 706 are disconnected, and the appliance
is operated as desired at 718. The process may be repeated as desired.
[0093] In the preceding example, the appliance 704 is described as including functionality
such as a load shifter 132 and disconnect requester 130 that are not supported by
the power supply 702. In one implementation, the functions supported by the devices
702, 704 are determined as part of an initial device identification step, with the
operation of the appliance 704 adjusted accordingly. In another, the appliance 704
does not determine the functions supported by the power supply 702 and is configured
to present load shift, disconnect, or other requests even though such requests may
not be recognized or acted upon by the power supply 702.
[0094] For the purpose of another example, it will assumed that the power supply is configured
as described in Figure 2C, while the appliance is configured as described in Figure
3C. A power supply - appliance interaction that includes a load shifting operation
will be described with reference to Figure 8.
[0095] The appliance and power supply are physically connected at 802.
[0096] The load shift requirements are determined at 804, for example by reference to a
load shift schedule, operating mode, and other information maintained in one or both
of the power supply and appliance, with the desired load shift operation being communicated
via the respective communications interfaces.
[0097] An operation of the appliance is temporally shifted at 806. For example, a desired
operation of the appliance may be deferred until a time at which the input power source
is subject to a relatively low power demand. In a case where the appliance is a battery
charger, for example, a requested charging operation may be restricted to a relatively
slow, low power mode during a designated high or peak demand period (
e.g., in the middle of the day for a typical AC power system) but permitted to operate
in a relatively faster, high power mode during a period of relatively reduced demand
(
e.g., during the night). The process may be repeated as desired.
[0098] In the case of an electrical appliance that includes an energy source, the appliance
may also be disconnected from the power supply and operated as desired as indicated
at 810 and 812 respectively.
[0099] An example power supply - appliance interaction that includes a load prioritization
information will now be described with reference to Figure 9 (not covered by the scope
of the invention), it being assumed that the power supply is configured to concurrently
connect to more than one appliance.
[0100] The power supply and a first appliance are connected at 902.
[0101] The power supply and appliance undergo a detection and/or identification operation
at 904. By way of example, the first device may be identified as a portable music
player including a rechargeable battery via a signal communicated over the devices'
respective communication interfaces.
[0102] The first appliance is operated at 906.
[0103] The power supply and a second appliance are connected at 908.
[0104] The power supply and appliance undergo a detection and/or identification operation
at 910. By way of example, the second device may be identified as a portable emergency
light also including a rechargeable battery by way of a signal communicated over the
devices respective communication interfaces.
[0105] The appliances are prioritized at 912, for example by applying a set of priority
rules applicable to various devices in a case where the power supply has insufficient
capability to concurrently power both devices. In the present situation, the priority
rules may provide that the emergency light takes precedence over the music player.
[0106] At 914, the appliances are operated according to the determined priority. In a first
example, the power supply may cause a first operating mode or priority signal to be
communicated to the emergency light via the devices' respective communication interface
so as to cause a charger of the emergency light to charge (or continue charging) the
emergency light battery. According to the first example, supply may cause a second
operating mode or priority signal to be communicated to the music player so as to
cause a charger of the emergency light to defer charging of the music player battery.
In another example, power supply alters a charging energy applied to the devices,
for example by limiting a charging voltage or current applied to the lower priority
device.